US5508841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spatial light modulator based phase contrast image projection system
Assignee: Texas Instruments Inc
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Filing: 1995-01-09
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Granted: 1996-04-16
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Expires: 2015-01-09
Abstract
Abstract A phase-contrast DMD based image system 36 for projecting an amplitude and phase modulated image. A flexure beam DMD array 34 is used to allow analog phase modulation of reflected light 38. The phase modulation is converted to amplitude modulation by the phase-contrast imaging optics including a phase plate 42. The resulting amplitude modulated wave is flicker-free and does not need to be synchronized to optical image sensors.
Inventors
- 👤 Tsen-Hwang Lin
- 👤 James M. Florence
- 👤 Michael Leddy
- 👤 Mark Boysel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:37
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/50; G02B27/52; G02B26/00; G02B26/06; G02B26/08; G02B26/0816; G02B26/0833; G02B26/0841
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
107 words
A method of amplitude modulation of visible and non-visible light comprising: providing a coherent incident beam of light having a selected frequency; deflecting at least one selected element of an array of deflectable micro-mirror elements; reflecting said incident beam of light from said deflected micro-mirror element to form a reflected beam of light, wherein the path of said reflected light is lengthened by said deflecting step, thereby altering the phase of said reflected light; focusing said reflected beam to separate the zeroth-order components from the other components; and altering the relative phase of said reflected beam to cause interference between said zeroth-order component and said other components.
Claim 2
Independent Claim
107 words
A method of amplitude modulation of visible and non-visible light comprising: providing a coherent incident beam of light having a selected frequency; deflecting at least one selected element of an array of deflectable micro-mirror elements; reflecting said incident beam of light from said deflected micro-mirror element to form a reflected beam of light, wherein the path of said reflected light is lengthened by said deflecting step, thereby altering the phase of said reflected light; focusing said reflected beam to separate the zeroth-order components from the other components; and altering the relative phase of said reflected beam to cause interference between said zeroth-order component and said other components.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said zeroth order is retarded π/2 radians.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said selected frequency of said incident beam of light is an infrared frequency.
Claim 5
Dependent Claim
18 words
The method of claim 1 further comprising the step of separating said reflected beam from said incident beam;
Claim 6
Dependent Claim
27 words
The method of claim 1 wherein each of said elements of said array of deflectable micro-mirror elements comprises a mirror suspended over an electrode by flexure hinges.
Claim 7
Dependent Claim
14 words
The method of claim 1 further comprising the step of attenuating said zeroth-order component.
Claim 8
Dependent Claim
98 words
An image display system comprising: a source of coherent light to project incident light along a light path; a micro-mirror device array having addressable mirror elements located in said light path for reflecting said incident light so as to shift the phase of said reflected light; a lens for focusing said reflected light, said focusing to separate said reflected light into a zeroth-order component and higher-order components; and a phase plate for altering the relative phase of said focused reflected light thereby causing interference between said zeroth-order component and said higher order components to produce amplitude modulated light.
Claim 9
Dependent Claim
98 words
An image display system comprising: a source of coherent light to project incident light along a light path; a micro-mirror device array having addressable mirror elements located in said light path for reflecting said incident light so as to shift the phase of said reflected light; a lens for focusing said reflected light, said focusing to separate said reflected light into a zeroth-order component and higher-order components; and a phase plate for altering the relative phase of said focused reflected light thereby causing interference between said zeroth-order component and said higher order components to produce amplitude modulated light.
Claim 10
Dependent Claim
13 words
The display system of claim 7 wherein said source is an infrared source.
Claim 11
Dependent Claim
13 words
The display system of claim 7 wherein said source is a visible source.
Claim 12
Dependent Claim
13 words
The display system of claim 7 wherein said source is an ultra-violet source.
Claim 13
Dependent Claim
20 words
The display system of claim 7 wherein said phase plate retards the zeroth-order of said reflected light by π/2 radians.
Claim 14
Dependent Claim
17 words
The display system of claim 7 wherein said phase plate attenuates the zeroth-order of said reflected light.
Claim 15
Dependent Claim
19 words
The display system of claim 7 further comprising a beamsplitter for separating said incident light from said reflected light.
Claim 16
Dependent Claim
64 words
An image display system comprising: an array having addressable modulator elements positioned to phase-modulate an incident beam of coherent light; means for separating said phase-modulated beam into a zeroth-order component and higher-order components; means for altering the relative phases of said components; and means for recombining said phase altered components so as to cause interference between said zeroth-order component and said higher order components.
Claim 17
Dependent Claim
64 words
An image display system comprising: an array having addressable modulator elements positioned to phase-modulate an incident beam of coherent light; means for separating said phase-modulated beam into a zeroth-order component and higher-order components; means for altering the relative phases of said components; and means for recombining said phase altered components so as to cause interference between said zeroth-order component and said higher order components.
Claim 18
Dependent Claim
20 words
The display system of claim 14 wherein said incident beam of coherent light is an infrared beam of coherent light.
Claim 19
Dependent Claim
20 words
The display system of claim 14 wherein said incident beam of coherent light is a visible beam of coherent light.
Claim 20
Dependent Claim
20 words
The display system of claim 14 wherein said incident beam of coherent light is an ultra-violet beam of coherent light.
Claim 21
Dependent Claim
21 words
The display system of claim 14 wherein said means for altering retards the zeroth-order of said separated light by π/2 radians.
Claim 22
Dependent Claim
18 words
The display system of claim 14 wherein said means for altering attenuates the zeroth-order of said separated light.
Claim 23
Dependent Claim
22 words
The display system of claim 14 further comprising a beamsplitter for separating said incident beam of coherent light from said phase-modulated beam.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-16 | 1999-10-16 | 2000-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-16 | 2003-10-16 | 2004-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-16 | 2007-10-16 | 2008-04-16 | $7700.00 | Window Closed / Lapsed |